1. Field of the Invention
This invention relates to a magneto electric generator rotor used in an internal combustion engine spark plug and an implement for removing this rotor.
2. Explanation of Prior Art
FIGS. 45 and 46 show a broken down section of a small size engine used in a conventional operating machine. In said figures numeral I is a small size engine, 1 is a cylinder for said engine 1, and 13 is a connecting rod supporting a piston that moves in this cylinder 12. Also, 14 is a crankshaft for eccentric driving the end of said con rod 13, and 15 is a nut to fix rotor B attached to the end of this crankshaft 14.
One side of said rotor B that is on the opposite side of an axial hole part through which the crankshaft 14 is inserted through secures a magnet 2 and forms a pole piece part P together with a magnetic pole 3, while the other side is composed of an insert core 26 of a ferromagnetic material that becomes counter weight part 4. Further, a cooling fan and the like is installed to this insert core 26 to form one body.
Numeral 6 is a non-magnetic material layer such as a synthetic resin layer formed in a discoidal shape so as to cover said insert core 26.
On one hand 7 is a ratchet claw which is supported in a freely revolving manner to an axle part 8 having a hole 8a as a cylinder part. Also, as shown in FIG. 46, a male screw 10 is inserted through this axle part 8, and the tip of this male screw 10 is screwed into and fixed to female screw 27 which has been formed beforehand in said insert core 26.
Numeral 9 is a ratchet spring of which one end is fixed to said axle part S, and the other end is fixed to said ratchet claw 7 and this gives a rotating force in one direction to the ratchet claw 7.
Also, a reel axle 29 is provided in one body so as to project into an operating machine frame 28 opposite to said rotor B. A reel 16 having continuously wound thereon a rope 17 is supported on this reel axle 29 in a freely rotating manner. On to this reel 16 provided with an engagement part 30 which catches said ratchet claw 7 and gives a rotating force to the reel 16.
A spiral spring 18 is installed in the periphery of said reel axle 29 to apply to said reel 16 a rotating force around this reel axle 29. 31 is a washer fixed to the end of the reel axle 29 by a screw 32 and serves as a protector to prevent the axle hole of the reel 16 from coming off of the reel axle 29. Moreover, the reel axle 29, the reel 16, the rope 17, the spiral spring 18. The engagement part 30, the ratchet claw 7 and the like form a recoil starter.
Also, 19 is a coil unit formed a power generating coil, ignition coil, ignition control circuit and the like in one body with thermosetting or thermoplastic synthetic resin and is fixed to said cylinder 12 side.
20 is a plug cap connected to said coil unit 19 through a cable 33. This plug cap 90 is connected to a plug 21 next to the cylinder 12. 28 is the operating machine frame housing an engine.
In a small size engine made of such a construction, the reel 16 rotates by manually pulling the rope 17 wound on this reel 16, and the engagement part 30 installed on said reel 16 catches on the ratchet claw 7 on rotor B which has a magnet 2 buried in the insert core 26, and rotates rotor B.
In this way, because said rotor B is attached to the crankshaft 14 of the engine 1, the crankshaft 14 is driven to rotate by said rotor B and the engine 1 is cranked up.
On one hand, at that time the magnetic flux of the magnet 2 attached to said rotor B interlinks with the coil unit 19 having an ignition control circuit fixed to the cylinder 12 side of said engine 1. Said coil} unit 16 will thus generate a power output and this power output will be supplied to the ignition plug 2 through the cable 3 q and the plug cap 20, and by this, the ignition plug 21 will generate a spark, ignite the gas mixture in the cylinder 12, and start up the engine 1.
Further, the fixing of the ratchet claw 7 described previously is done by screwing in the axle part 8 supporting it in a ratable manner to the insert core 26 of the male screw 10. For this reason the female screw 27 conforming to the male screw 10 is machine tooled as aforementioned in the said rotor B.
On one hand, the rotor shown in FIGS. 47 and 48 has been proposed in the past as a rotor used in a magnetic power generating machine such as the one described above. This rotor B I is a rotor having a hole piece part 44 with a magnet 42 on one side and an insert core 41 as a counter weight part 45 on the opposite side of an axial hole part 43 buried as an insert form within a synthetic resin (not shown). This rotor B1 is described in, for example Japanese Utility Model Publication 1993-10526.
In this conventional rotor B I, the insert core 41 has been made into an integrated unit with a rivet 47 riveting together layers of multiple magnetic plates in multiple locations, and said axial hole part 43 is a straight hole with the diameter being equal in the direction of the axle.
Also, of the 3 magnetic poles, 46, 46a and 46b forming the pole piece 44, said magnet 42 is inserted in an open hole 49 formed in the center magnetic pole 46, and both ends of the magynet protrude outward towards the axial fringe of each magnet pole 46, 46a and 46b.
In such insert core 41, the pole piece part 44 and the counter weight part 45 are formed in one body. and because there is no need for assembly work and machine tooling after die casting the advantage of a relatively low cost is achieved.
On one hand, in the past, when removing the rotor of a magnetic power generator from the crankshaft 14 of an engine such as shown in FIG. 45, a pulley removing tool is used to remove the pulley attached to the rotary axle.
FIG. 49 shows such a conventional pulley removing tool and a rotor B2 of a magnetic power generator removed therewith. In said drawing, 14 is the engine crankshaft, and this crankshaft 14 is provided with an axial hole 43 for rotor B2 having a magnet and counter weight and the like, and made in a virtually circular form with a non-magnetic material.
Also, said rotor B2 is fixed to the crankshaft 14, so as not to come off freely, with a nut 15 screwed on a male screw part 48 formed on the crankshaft 14 end. Moreover, F is a multiple bladed cooling fan installed along the circuit direction of one side of the rotor B2.
On one hand 50 is a bolt attachment part on which a bolt 51 is screwed on at the center part and to both ends are connected arms 52 and 53 through axle supports 54 and 55, and a disengragcement claw 53a is installed on the tip of the arm 53.
With this pulley removing tool, first the disengagement claw 53a of each of said arm 53 ends is disengaged at the inner surface of the outer circuit part of the rotor B2 that is pressed against the crankshaft 14 and the tip of said bolt 15 is pressed against the tip of the crankshaft 14.
Further, the nut 15 is removed from the male screw part 48 before and after such operation, then said bolt 51 is screwed on the attachment part 50. With this, the arms 52 and 53 will be subjected to an axial directed torque due to the screwing on power and change the position of the supporting axles 54 and 55 to the center, and the rotor B2, which was being held by the disengaging claw 53a, is removed in the axial direction from the crankshaft 14.
FIG. 50 shows a conventional rotor removal tool and a rotor B2 of a magnetic power generator that is removed with said tool. In the drawing 56 is multiple screw holes provided on the rotor B2 so as to pass through both sides of said rotor.
Also, 57 is a male screw, whose tip can be screwed into the screw hole 56. Said male screw 57 is screwed into a through hold 59 provided in a plate 58 and the male screw 57 is prevented from pass in through by a screw head 57a.
On to said plate 58, a bolt 51 is screwed into its center part and it is possible for the tip of the bolt to hit the tip of said crankshaft 14.
According to this removal tool, the tip of the male screw 57 is screwed into said screw hole 56 in certain depth. then said bolt 51 is screwed into the plate 58 until the tip of the bolt 51 hits the end of the crankshaft 14.
Then, while keeping said plate 58 in a position that is parallel to the rotor B2, said bolt 51 is screwed in. By doing this, the power to remove the rotor B2 from the crankshaft 14 is provided to the rotor through the male screw 57 in the plate 58. For this reason the rotor B2 can be smoothly removed from the crankshaft 14.
However, with a rotor B of a conventional magnetic power generator such as that shown in FIGS. 45 and 46. even at present when the nonprocessing of the rotor B has become advanced, but only the processing of the screw (female screw) 27, which is used for fixing said ratchet claw 7 cannot be eliminated. For this reason a reduction in cost could not be achieved.
Also, with a rotor using an insert core of layered magnetic plates and formed into an approximately circular shape with plastic the processing of said screw for use in attaching the ratchet could not be carried out without performing special work such as inserting aluminum parts.
Also, because the axial hole part 43 is a straight hole in the rotor B I of the conventional magnetic power generator shown in FIGS. 47 and 48, when assembling said axial hole part 43 to the crankshaft 14 of the internal combustion engine, it is difficult to provide sufficient cohesive strength to both parts. Also, in order to provide sufficient cohesive strength to both parts, it is necessary to use a separately prepared cohesion aid tool.
Also, in order to provide sufficient cohesion strength to said axial hole part 43 and said rotor B I, said axial hole part 43 can be made into a tapered hole and tighten the bond between both parts. However, in said layered insert core 41, the tapered hole will be terraced with each layer of the plate. For this reason, the contact with said crankshaft 14 will become shaky and the cohesion between both parts will be imperfect.
Further, because both ends of the magnet 42 protruded out (out of the thickness) in the axial fringe direction Z of each magnetic pole 46, the magnetic flux of said magnet 42 could not be sufficiently concentrated on magnetic pole 46. That is a part of the magnetic flux would leak outside the magnetic pole 46 and will not reach the power generating coil and ignition coil. For this reason, the power generating capacity for ignition and the like cannot be sufficiently generated.
Also, when using a layered insert core 41 in an attempt to sufficiently bring out the capacity of said magnet 42, it will be necessary to increase the thickness of the layers which results in increase of weight of whole rotor. Also, in case the layered thickness is altered partially, the increase of initial cost accompanying the increased cost for press molds and the increase in the process steps and costs cannot be avoided.
Further, it has been proposed that an insert core 41 be formed with a magnetic sintered alloy and said magnet introduced between the insert core 41 and the magnetic pole on the support provided thereon. However, in this case it will be necessary to make the support fairly thick due to the conditions for forming.
For this reason, this support will invite shortages in the magnetic circuit and the magnetic flux generation rate in said magnetic pole will deteriorate, and the power generating capacity in said power generating coil and the like will also become inadequate.
Further, in the removal method for rotor B2 shown in FIG. 49, it will be necessary to disengage the disengaging claw 53 along the outer surface of the rotor B2. At present, when miniaturization of the magnetic power generator and engine is being aimed at, it is difficult to keep the space required for such a disengagement claw 53 on the peripheral of said rotor B2, and as a result such a pulley removal tool cannot be practically used.
Also, in the removal method shown in FIG. 50, it is necessary to apply an additional process of a screw hole 3 S for the rotor obtained by molding to the latter steps of processing, and the non-processing of the rotor B2 cannot be realized which will invite a decrease in production efficiency and an increase in cost.